Student Noah Sturdy demonstrates how to caulk a boat seam.
Wikipedia: “Traditional caulking (also spelled calking) on wooden vessels uses fibers of cotton and oakum (hemp fiber soaked in pine tar). These fibers are driven into the wedge-shaped seam between planks, with a caulking mallet and a broad chisel-like tool called a caulking iron.The caulking is then covered over with a putty, in the case of hull seams, or else in deck seams with melted pine pitch, in a process referred to as paying.”